Environmental Chemistry · JEE Main previous year questions

The molecule that has minimum /no role in the formation of photochemical smog, is :

1. A.$\mathrm{C}{\mathrm{H}}_2=\mathrm{O}$
2. B.${\mathrm{O}}_3$
3. C.${\mathrm{N}}_2$
4. D.$\mathrm{NO}$

The compound that is NOT a common component of photochemical smog is :

1. A.${\mathrm{O}}_3$
2. B.${\mathrm{H}}_3\mathrm{C}-\mathrm{CO}-\mathrm{OON}{\mathrm{O}}_2$
3. C.$\mathrm{C}{\mathrm{H}}_2=\mathrm{CHCHO}$
4. D.$\mathrm{C}{\mathrm{F}}_2\mathrm{C}{\mathrm{l}}_2$

The correct match between Item I and Item II is : $$\begin{array}{llll}\text{Item I}& & \text{Item II}& \\ \text{(A)}& \text{Allosteric effect}& \text{(P)}& \text{Molecule binding to the active site of enzyme}\\ \text{(B)}& \text{Competitive inhibitor}& \text{(Q)}& \text{Molecule crucial for communication in the body}\\ \text{(C)}& \text{Receptor}& \text{(R)}& \text{Molecule binding to a site other than the active site of enzyme}\\ \text{(D)}& \text{Poison}& \text{(S)}& \text{Molecule binding to the enzyme covalently}\end{array}$$

1. A.(A)$\to$(P); (B)$\to$(R); (C)$\to$(Q); (D)$\to$(S)
2. B.(A)$\to$(P); (B)$\to$(R); (C)$\to$(S); (D)$\to$(Q)
3. C.(A)$\to$(R); (B)$\to$(P); (C)$\to$(S); (D)$\to$(Q)
4. D.(A)$\to$(R); (B)$\to$(P); (C)$\to$(Q); (D)$\to$(S)

The recommended concentration of fluoride ion in drinking water is up to 1 ppm as fluoride ion is required to make teeth enamel harder by converting $[3{\text{Ca}}_3({\text{PO}}_4{)}_2.\text{Ca}(\text{OH}{)}_2]$ to

1. A.$[3\{\text{Ca}(\text{OH}{)}_2\}.{\text{CaF}}_2]$
2. B.$[{\text{CaF}}_2]$
3. C.$[3({\text{CaF}}_2).\text{Ca}(\text{OH}{)}_2]$
4. D.$[3{\text{Ca}}_3({\text{PO}}_4{)}_2.{\text{CaF}}_2]$

Which of the following is a set of greenhouse gases?

1. A.$\mathrm{C}{\mathrm{H}}_4$, ${\mathrm{O}}_3$, ${\mathrm{N}}_2$, $\mathrm{S}{\mathrm{O}}_2$
2. B.${\mathrm{O}}_3$, ${\mathrm{N}}_2$, $\mathrm{C}{\mathrm{O}}_2$, $\mathrm{N}{\mathrm{O}}_2$
3. C.${\mathrm{O}}_3$, $\mathrm{N}{\mathrm{O}}_2$, $\mathrm{S}{\mathrm{O}}_2$, $\mathrm{C}{\mathrm{l}}_2$
4. D.$\mathrm{C}{\mathrm{O}}_2$, $\mathrm{C}{\mathrm{H}}_4$, ${\mathrm{N}}_2\mathrm{O}$, ${\mathrm{O}}_3$

Identify the pollutant gases largely responsible for the discoloured and lustreless nature of marble of the Taj Mahal.

1. A.${\mathrm{O}}_3$ and $\mathrm{C}{\mathrm{O}}_2$
2. B.$\mathrm{C}{\mathrm{O}}_2$ and $\mathrm{N}{\mathrm{O}}_2$
3. C.$\mathrm{S}{\mathrm{O}}_2$ and $\mathrm{N}{\mathrm{O}}_2$
4. D.$\mathrm{S}{\mathrm{O}}_2$ and ${\mathrm{O}}_3$

The synthesis of alkyl fluorides is best accomplished by:

1. A.Sandmeyer’s reaction
2. B.Finkelstein reaction
3. C.Swarts reaction
4. D.Free radical fluorination

Water sample is reported to be highly polluted if BOD (Biological Oxygen Demand) value of sample becomes

1. A.more than $17\mathrm{ppm}$
2. B.equal to $10\mathrm{ppm}$
3. C.equal to $5\mathrm{ppm}$
4. D.less than $5\mathrm{ppm}$

Green house gases can be arranged in 'Global Warming Potential' sequence as

1. A.${\mathrm{N}}_2\mathrm{O}>\mathrm{CFC}>\mathrm{C}{\mathrm{H}}_4>\mathrm{C}{\mathrm{O}}_2$
2. B.$\mathrm{CFC}>{\mathrm{N}}_2\mathrm{O}>\mathrm{C}{\mathrm{H}}_4>\mathrm{C}{\mathrm{O}}_2$
3. C.$\mathrm{CFC}>\mathrm{C}{\mathrm{O}}_2>{\mathrm{N}}_2\mathrm{O}>\mathrm{C}{\mathrm{H}}_4$
4. D.$\mathrm{C}{\mathrm{O}}_2>\mathrm{CFC}>{\mathrm{N}}_2\mathrm{O}>\mathrm{C}{\mathrm{H}}_4$

Percentages of free space in cubic close packed structure and in body centred packed structure are respectively :

1. A.30% and 26%
2. B.26% and 32%
3. C.32% and 48%
4. D.48% and 26%

Insulin production and its action in human body are responsible for the level of diabetes. This compound belongs to which of the following categories?

1. A.A co- enzyme
2. B.An antibiotic
3. C.An enzyme
4. D.A hormone

The smog is essentially caused by the presence of :

1. A.${\mathrm{O}}_2$ and ${\mathrm{O}}_3$
2. B.${\mathrm{O}}_3$ and ${\mathrm{N}}_2$
3. C.Oxides of sulphur and nitrogen
4. D.${\mathrm{O}}_2$ and ${\mathrm{N}}_2$

The heat required to raise the temperature of body by 1 K is called :

1. A.specific heat
2. B.thermal capacity
3. C.water equivalent
4. D.none of these